Abstract: Introduction: Posterior uveitis (PU) and retinal vasculitis (RV) usually progress toward severe loss of vision or blindness, if not aggressively treated. The aim of this study is to evaluate the efficacy of Pulse Cyclophosphamide (PCP) in a cohort study. Methods: This study includes all patients treated with PCP from 1986 to 1998, for active PU and or RV. PCP was administered as Ig cvclophosphamide/m2/body surface, once per month. Prednisolone was given daily as 0.5 mg/kg. A Disease Activity Index (DAI) was calculated for PU and RV. Visual acuity (VA) was evaluated for each eye. A Total Adjusted Disease Activity Index (TADAI) was calculated for each patient by adding the different adjusted DAI (according to their aggressiveness) and VA together. Results: The mean follow up time was 23.8 months (minimum 6, maximum 90 months). The mean PCP was 12.8 per patient. The entry data were as follows: mean DAI was 2.3 for PU and 2.2 for RV. The mean VA was 3.3, and the mean TADAI 40.4. After the treatment the mean DAI improved to 1.2 (p<0.0001) for PU and to 1.3 (p<0.0001) for RV. The mean VA improved to 3.8 (p<0.007), and the mean TADAI to 31.2 (p<0.0001), PU improved in 52%, RV in 51% and VA in 37% of the eye, and TADAI in 53% of patients. Conclusion: PCP is effective in short and in long-term treatment. It is safe and easy to use. Results, when compared to other cytotoxic drugs, were the same with no statistically significant difference between them (A & R 1996; 39: S217, abs 1141).